EGR cooler recall and limp mode

WaynesTDI

Veteran Member
Joined
May 23, 2007
Location
Eastern CT
TDI
'04 Jetta Wagon
If you've been having limp mode issues since an EGR cooler replacement, I've stumbled upon one cause of it.

I've been having problems for almost 5 months since it was done, spent $3K in repairs at three different shops that have done nothing (Including a new turbo), and just last friday I walked out on a Honda dealer when I was in there to take delivery on a new car, because they tried to hose me on the trade-in of my '04 Jetta TDI Wagon that nobody could fix. I decided it was cheaper to keep the TDI and just deal with it.

After that, I made an appt with MRCHILL's shop to have it looked at, and decided that I'd keep tinkering in the interim, because I had good reason to suspect that it was a vacuum issue, despite the fact that the dealer claims to have tested the system, and found no leaks.

Last night, I was re-checking all the vacuum lines and connections for the 10th time at least, and something that had bugged me when I re-plumbed part of the system jumped out at me again: The vacuum connection to the EGR cooler actuator seemed to be too easy to put on and remove. I noticed that when I first replaced that section of hose, and I used stock ID hose that fit snugly everywhere else, so I didn't consider that it would be an issue. So, I pulled the line off, got a flashlight, and took a good look at the nipple on the actuator ---- IT'S SMALLER THAN THE ID OF THE HOSE. I wasn't aware that there were two different sizes of nipple on the actuator, so I never considered it. Possibly the actuator was meant for a pre-PD engine?I took a section of 3mm ID high-temp silicone hose, and replaced the stock hose with it. I didn't think it would accomplish anything, but at least it made me feel better. And it was good and tight now.

I drove to work this AM, and noticed a smooth power curve, and balls to spare on hills. Hmmmmmmm.........So I went for a drive at lunchtime today, and took her out on the highway for a little thrashing, totally expecting to find myself once more in limp mode. Not on the trip out. On the way back, I accelerated to 90 MPH on the entrance ramp, and when I got to the bottom of a decent hill, I floored it. I was doing 115 MPH at the top, still accelerating, and my CEL shut off! Smooth power, and lots of it. No stumbling, no overboost, no limp mode.

I'll have to drive it for another week or so without any issues to be certain that I got it this time. If I do have it, the service manager at the dealership and I are going to have a little "chat" (More like me yelling and him listening - I'm very good at that).
 

WaynesTDI

Veteran Member
Joined
May 23, 2007
Location
Eastern CT
TDI
'04 Jetta Wagon
As a follow-up, I took the car in for an oil change and air filter, cabin air filter, etc etc etc for the 80K service, and when I got the car back at the end of the day --- immediate limp mode and a CEL.

So I decided no more screwing around. I went out and bought a Mityvac tester, and tested the EGR cooler actuator --- massive vacuum leak. Every other component in the vacuum system checks out OK.

The weird thing is that in testing the EGR cooler actuator, I seem to have re-set it, because on my way to work this AM, the CEL went off the first time I dug into the turbo, and the car runs great again.

So it appears that the EGR cooler is defective beyond having the wrong size vacuum nipple.....and still under warranty for another month. The dealer isn't going to enjoy the phone conversation we're going to have this AM.
 
Top